[PATCH v9 0/2] Adds PMU and S2R support for exynos5420

[Javier Martinez Canillas]

Hello Abhilash,

On Thu, Oct 9, 2014 at 4:37 AM, Abhilash Kesavan
<kesavan.abhilash at gmail.com> wrote:
> Hi Kevin,
>
> On Thu, Oct 9, 2014 at 4:49 AM, Kevin Hilman <khilman at kernel.org> wrote:
>> Vikas Sajjan <vikas.sajjan at samsung.com> writes:
>>
>> [...]
>>
>>> Tested on Kukjin Kim's tree, for-next branch +
>>> 1] http://www.spinics.net/lists/linux-samsung-soc/msg33750.html
>>> 2] https://www.mail-archive.com/linux-samsung-soc@vger.kernel.org/msg37260.html
>>> 3] with the CLK_IGNORE_UNUSED flag for aclk200_disp1 CLK
>>>
>>> on Exynos5420 based chromebook (peach-pit board)
>>>
>>> Below procedures were followed to test S2R:
>>> Procedure A:
>>>       1. make multi_v7_defconfig
>>>       2  enable MCPM for 5420
>>>       3. enable S3C RTC
>>>       5. echo +20 > /sys/class/rtc/rtc0/wakealarm && echo mem > /sys/power/state
>>> Procedure B:
>>>       1. make exynos_defconfig
>>>       4. echo +20 > /sys/class/rtc/rtc0/wakealarm && echo mem > /sys/power/state
>>
>> I went tried to this on exynos5800-peach-pi and found first that
>> exynos_defonfig is missing the MAX77802 kconfig options for the RTC
>> source clock:
>>
>> CONFIG_REGULATOR_MAX77802=y
>> CONFIG_COMMON_CLK_MAX77802=y
>
> I am using exynos_defconfig (no changes) with the internal SoC RTC
> which is enabled by default. I did not enable the MAX77802 RTC.

That is because you probably are using kukjin's for-next branch as a
base but I had the same issue when testing s2r on linux-next.

The problem is that linux-next contains commit 546b117fdf17 ("rtc:
s3c: add support for RTC of Exynos3250 SoC") that added a required
"rtc_src" DT property for the Samsung's S3C RTC that is used to
specify the source clock XrtcXTI.

On Peach boards, the S3C source clock is the max77802 32kHZ AP clock
so I fixed that with commit 8bd43b6 ("ARM: dts: Add rtc_src clk for
s3c-rtc on exynos Peach boards") but didn't send a patch to enable the
max77802 subdevices on exynos_defconfig.

I'll post a patch to enable those config options today and maybe they
can be considered as -rc material.

>>
>> With those, rtc0 then comes up, but isn't waking from suspend.  However,
>> writing something to rtc0/wakealarm does result in /proc/interrupts
>> having an interrupt for the RTC, it's just not waking the system.
>>
>> Anyone else tried this on 5800/peach-pi?
>
> I have tested this on a Peach-Pi and the system is resuming fine. The
> patches applied on kgene's for-next branch along with the
> aclk200_disp1 fix are:
> http://lkml.org/lkml/2014/9/30/156
> https://lkml.org/lkml/2014/10/6/89
> http://www.spinics.net/lists/arm-kernel/msg368207.html
> http://www.spinics.net/lists/linux-samsung-soc/msg37647.html
>

Kevin, I didn't test it on 5800 peach pi but I did test it on 5420
peach pit and as Abhilash said, I also needed Vikas patch [0] to flag
the aclk200_disp1 and aclk300_disp1 clocks as CLK_IGNORE_UNUSED to
prevent the ccf to disable them. With that patch Suspend-to-Ram worked
for me and resuming using both the internal S3C RTC and the max77802
RTC.

Also I tested the pm_tests and all of them passed on my peach pit.

On peach pi you shouldn't need the clock patch AFAIU if you enable the
needed kconfig options to have display working since those clocks are
used by the display controller so they won't be disabled due unused.

Hope it helps,
Javier

[0]: http://www.spinics.net/lists/arm-kernel/msg367197.html